//  boost timer.hpp  ---------------------------------------------------------//

//  Copyright Beman Dawes 1994-2007

//  Distributed under the Boost Software License, Version 1.0.
//  See http://www.boost.org/LICENSE_1_0.txt

//  See http://www.boost.org/libs/system for documentation.

#ifndef BOOST_ENDIAN_TIMER_HPP                  
#define BOOST_ENDIAN_TIMER_HPP

#include <boost/config/warning_disable.hpp>

#include <boost/endian/detail/config.hpp>
#include <boost/system/error_code.hpp>
#include <boost/cstdint.hpp>
#include <string>
#include <cstring>
#include <ostream>

#include <boost/config/abi_prefix.hpp> // must be the last #include

namespace boost
{
  namespace endian
  {
    typedef boost::int_least64_t microsecond_t;

    struct times_t
    {
      microsecond_t wall;
      microsecond_t user;
      microsecond_t system;

      void clear() { wall = user = system = 0LL; }
    };

    //  low-level functions  -------------------------------------------------//

    BOOST_ENDIAN_DECL
    void  times(times_t& result); // throws on error

    BOOST_ENDIAN_DECL
    system::error_code& times(times_t& result, system::error_code& ec); // never throws

    //  timer  ---------------------------------------------------------------//

    //  unless otherwise specified, all functions throw on error

    class BOOST_ENDIAN_DECL timer
    {
    public:

      timer()                         : m_flags(m_stopped) { start(); }
      timer(const std::nothrow_t&) : m_flags(static_cast<m_flags_t>(m_stopped
                                                  | m_nothrow)) { start(); }
     ~timer()                         {}  // never throws

      void            start();
      const times_t&  stop();
      bool            stopped() const { return m_flags& m_stopped; }
      void            elapsed(times_t& result); // does not stop()

    private:
      times_t    m_times;
      enum       m_flags_t { m_stopped=1, m_nothrow=2 };
      m_flags_t  m_flags;
    };

    //  run_timer  -----------------------------------------------------------//

    //  unless otherwise specified, all functions throw on error

    class BOOST_ENDIAN_DECL run_timer : public timer
    {
    public:

      // each constructor has two overloads to avoid an explicit default to
      // std::cout, which in turn would require including <iostream> with its
      // high associated cost even when the standard streams are not used.

      explicit run_timer(int places = 2);

      run_timer(int places, std::ostream& os)
        : m_places(places), m_os(os), m_format(0) {}

      explicit run_timer(const std::string& format, int places = 2);

      run_timer(const std::string& format, int places, std::ostream& os)
         : m_places(places), m_os(os), m_format(new char[format.size()+1])
           { std::strcpy(m_format, format.c_str()); }

     ~run_timer()  // never throws
      { 
        system::error_code ec;
        if(!stopped())
          report(ec);
        delete [] m_format;
      }

      void        report();
      system::error_code
                  report(system::error_code& ec); // never throws

    private:
      int             m_places;
      std::ostream&   m_os;
      char*           m_format;  // doesn't use std::string as VC++ too painful
                                 // across DLL boundaries due to warning C4251
    };
    
  } // namespace endian
} // namespace boost

#include <boost/config/abi_suffix.hpp> // pops abi_prefix.hpp pragmas

#endif  // BOOST_ENDIAN_TIMER_HPP